In all vertebrate animals, including humans, osseous structures provide an essential solid framework for the body. Injury, age or disease may however damage these osseous structures. In order to repair or at least alleviate such damage, various medical and surgical techniques have been proposed. In particular, a number of surgical techniques have been proposed using wire ligatures to reinforce or correct such injured, diseased, or otherwise damaged osseous structures.
Surgical wiring techniques have in particular been applied for treatment of the spine, and more especially of upper cervical fractures and thoraco-lumbar fractures. For example, the Gallie and Brooks atlanto-axial stabilization techniques using wires can be used for the treatment of Type II and III C2 odontoid fractures, i.e., fractures at the base of the C2 odontoid or transversally to the body of the C2 vertebra; as well as Type III C2 traumatic spondylolisthesis, i.e., C2 “hangman fractures” with severe displacement and angulation. The Wertheim and Bohlman occipitocervical stabilization technique can be used for the treatment of fractures of the closed ring of the C1 vertebra, as well as for the stabilization of the C1-C2 segment when affected by rheumatoid arthritis.
Trauma, such as distractive flexion injuries with facet disruption and dislocation, or ligamentous injuries, to other cervical segments, for instance at the C5-C6 level or at the fulcrum between cervical and thoracic spine, can be treated using subaxial cervical stabilization with such wiring techniques as the Rogers technique, the Bohlman triple wire technique, the Dewar technique, or the Robinson and Southwick facet wiring technique.
Finally, among the thoraco-lumbar fractures that can be reduced and stabilised using wiring techniques, and in particular Harrington rods with sublaminar wires and interspinous wires, are compression fractures, flexion distraction fractures (“seatbelt fractures”), and dislocated fractures.
However, the metallic wires used in such wiring techniques present some drawbacks, in particular with respect to biocompatibility, strength, stability and material fatigue, and stress concentrations where they contact the bones. Even more significantly, adjusting the wire tension while tying the wire requires very high dexterity, and may be even more difficult once the wire is tied.
In the prior art, it has also been proposed to use flexible elongated elements other than wires to tie various implants to underlying osseous structures. In particular, intervertebral implants have been proposed which are tied to the vertebrae using flat bands, for instance in International Patent Application publication WO 2009/040380. Such flat bands have the advantages of higher biocompatibility, strength and stability, as well as better stress distribution on the bones. While adjusting the band tension remains difficult, this is less critical in this application, since the main stresses go through the body of the intervertebral implant, rather than the flat band.